You must have the National Dex to get the Up-Grade. Go to the Pal Park and Prof Oak will be there. He will say he is staying in Eterna City. Go to Eterna City and walk to the South - Western house. Talk to Prof Oak again and he will give you the Up-Grade to Level up your Porygon to a Porygon 2
the upgrade is used to evolve porygon into porygon-z
It evolves Porygon to Porygon2 through trade.Dubious disc will then change Porygon2 to PorygonZ
You give it to a Porygon and trade it, to get a Porygon 2.
If you give it to porygon and trade it, porygon will evolve
you give porygon the upgrade then trade it to get a porygon 2 then you give your porygon 2 another upgrade and trade yet again to get a porygon-z
The dubious disc is to be used with a Porygon 2. First, you must have obtained the porygon. To get a porygon 2, you trade a porygon to someone with it holding an upgrade from Silph Co., and then trade it back again with the dubious disc to get Porygon Z.
You can use Upgrade to evolve your Porygon into Porygon 2. To do this. Make your Porygon hold the Upgrade in a trade. (This will only work if trading it to a G/S or newer game.)
you cant find a porygon ,you can find it in Pokemon pearl or on platinum
Give porygon an upgrade and trade it it evolve it. And of course you have to trade it back. Try this in Pokémon go!
you can make porygon hold it then you trade it and it turns into a porygon-2
Porygon is found rarely in the Trophy Garden.
its used to evolve porygon into porygon 2.to do that you have to have porygon hold it,then trade him.